1. Field of the Invention
This invention relates to a multi-functional air circulation system, particularly to one having its main engine and its bottom base differently assembled, so that it can be used as a fan only or a fan with additional functions, such as dispersing fragrance, getting rid of bugs, filtering off impurities in air and humidifying air.
2. Description of the Prior Art
As disclosed in a Taiwan patent No. 366963 “MULTI-FUNCTIONAL ELECTRIC FAN”, the conventional fan includes a left and a right positioning base provided in a lower cover of a main body, with the left positioning base installed with a motor for forcing a driving mechanism to keep a driving rack moving up and down. The lower cover of the main body is provided with a base located at its bottom for pivotally connected with a linking rod. An upper cover is located above the lower cover of the main body, provided with a motor hood groove, a linking rod groove for fitting the linking rod, a rack hole for the driving rack to pass through, and an essence groove used for containing essence. The top of the driving rack can be pivotally fixed with an ear of a rear fan covering. The linking rod has its front end pivotally fixed at a center of a lower portion of the rear fan covering. A motor is installed in a motor hood that is positioned on the rear fan covering. Located in front of the rear fan covering is a front fan covering, and a fan is installed between the front fan covering and the rear fan covering.
However, as the essence groove is additionally installed in the upper cover of the main body and the fan must be driven by the additional driving rod, the conventional fan is obviously composed of complicated components, posing a high manufacturing cost.